“America is NOT the greatest country in the world,” news commentator Will McAvoy barks, in answer to a seemingly simple question from a student during a college forum: “Can you say why America is the greatest country in the world?”

Up to that moment, McAvoy had been diffident, jokey and noncommittal, living up to a forum moderator’s description as the “Jay Leno of news anchors. You’re popular because you don’t bother anyone.”

But in an instant, McAvoy’s world changes.

Played by Jeff Daniels in the new HBO series, “The Newsroom,” McAvoy’s vitriolic diatribe (about the decline of the country’s standing in most relevant world-rankings) becomes a YouTube sensation—and that moment unleashes something life-changing in McAvoy. He’s never previously voiced strong opinions publicly: about politics, the media and the alternately synergistic and cannibalistic relationship between the two. When he does, he finds himself at the center of a firestorm because he finally felt compelled to “speak truth to stupid.”

That opening crisis becomes the pivot point in “The Newsroom,” written by Aaron Sorkin, who won an Oscar as screenwriter of The Social Network (about Facebook), and multiple Emmy Awards as the creator of “The West Wing,” the long-running series that took an inside look at White House politics.

Politics—in the broadest sense—can’t help but also be at the center of “The Newsroom.” And it’s a given: “The Newsroom” will raise hackles, which is, after all, Sorkin’s trademark.

“When this airs, the guy who’s sitting in his Barcalounger watching is either going to go, ‘Hell, yeah!’—or he’ll throw his beer at the TV screen,” Daniels says. “There will be a reaction. This one is heading for the water cooler.”

But then, that’s what Sorkin does: He forces viewers to think, creating controversy in the process.

“TV is something we use as background music, or for company,” Sorkin notes. “But the stuff I write doesn’t work well if you use it as that. The audience that comes to HBO knows they need to pay attention.”

That’s why HBO began courting Sorkin, even before he had the idea for the series, says Michael Lombardo, HBO’s president of programming.

“When I first got this job, [HBO copresident] Richard Plepler and I were talking about writers we loved, and Aaron’s name was at the top of the list,” Lombardo says. “So we went to lunch with him—this is three or four years ago—and said, ‘We love you and your writing and we want you to think about what we might do together.’ ”

They continued to check in with him as he worked on films such as The Social Network and Moneyball. “Then we got a call that he’d written a script,” Lombardo continues. “And we knew from the first draft that we wanted to do it.

“There are writers—and then there’s Aaron Sorkin. There’s nobody who can weave a story and write dialogue like Aaron at his best. And I believe this is Aaron at his best.”

Though he’d just won an Oscar for The Social Network, Sorkin, who became a playwright (A Few Good Men) after struggling as an actor, was eager to get back to television.

“The schedule is ferocious, but I love series TV,” Sorkin says. “You get to tell a different kind of story. A season of shows is like the chapters in a book. Each season is like a book in a series.”

Over the course of the first season’s 10 episodes, McAvoy’s show, “News Night,” will change from innocuous to confrontational, as McAvoy—goaded by his new producer (and former girlfriend)—makes the decision to be blunt, rather than filtering himself. McAvoy’s transformation from someone who has strenuously avoided controversy to someone who unleashes it causes a panic among the network’s executives, particularly its bottom-line-obsessed owner, played by Jane Fonda (perhaps channeling ex-husband Ted Turner).

In focusing on the cable news world, Sorkin has plenty of fodder, particularly about partisan divisiveness and the media as enabler, rather than explainer or debunker, of political lies and half-truths. But that’s not Sorkin’s only focus.

Rather, he says, the show’s plot will be built on the relationships in the newsroom, particularly the one-time romance between McAvoy and his new producer, MacKenzie MacHale (Emily Mortimer), a triangle between McAvoy’s assistant (Alison Pill), his former producer (Thomas Sadoski) and MacKenzie’s right-hand man (John Gallagher Jr.). And that’s not to mention the professional give-and-take between McAvoy, his boss (Sam Waterston) and the network chief.

Notes Daniels, “Over the course of the series, Aaron also gets to write funny. And he’s got people in this cast who know where the jokes are.”

While Sorkin’s writing definitely is funny, it’s also both pointed and sharp-edged, as well as topical (without focusing on the headlines of the moment). Which means that “The Newsroom” is not a show that will leave viewers neutral.

But as Sorkin (who won or shared five Emmy Awards for his work on “The West Wing”) is quick to note, politics is never his first focus.

“I wouldn’t even say politics is second on the list. It’s probably fourth or fifth,” says Sorkin, 51. “I hope the success or failure of this show has nothing to do with whether people agree or disagree with the characters. This show is not hammering home one political point. But it does bring up things people disagree about. I have no political agenda. My goal isn’t to persuade or preach.”

In fact, the show is as much about McAvoy’s personal life as his work: specifically, his contentious relationship with his bosses, his ill-tempered treatment of his underlings and his involvement with his new executive producer, a former lover who shattered him a few years earlier when she walked away from their relationship. McAvoy is notoriously prickly (even though he argues loudly, “I’m AFFABLE!”). But he’s not knee-jerk about anything. “I’m a registered Republican,” the character says early on. “I only seem liberal because I happen to believe that hurricanes are caused by high barometric pressure and not gay marriage.”

As Sorkin explains: “I do like writing in a romantic, idealistic, swashbuckling style... I like workplace shows, with people in the trenches. A newsroom is a place where all kinds of stories come in over the transom.”

While Sorkin has nothing but kind words for his experiences working for ABC (“Sports Night”) and NBC (“The West Wing,” “Studio 60 on the Sunset Strip”), he acknowledges that cable offered several advantages. “Obviously, there’s the language—every once in a while, I can use language I wouldn’t have been able to use on the networks,” Sorkin says. “But the biggest creative difference is that each episode feels like a one-hour movie. It’s not broken up by commercials. And there are different things I can do, subject-wise, on HBO that I would have gotten notes from the network about.”

Notes Lombardo, “He doesn’t have to worry about being too political.”

Is there such a thing as too political for HBO? “Well, we’re the home of Bill Maher,” Lombardo says, “so I’d say we haven’t yet gotten to the outer bounds of that.”

Sorkin’s presence—and the quality of his work—is what attracted Daniels to the series, after years of resisting the notion of working in TV.

“There’s a musicality to Aaron’s writing. It’s so well-written,” says Daniels. “When I got this show, I heard from my friend Tim Busfield (who was part of the cast of Sorkin’s “The West Wing”) and he said, ‘Wait until you see the stuff you get to say.’ “You have to learn it so you can make it appear as if you’re thinking and saying these things at that moment, at 100 miles per hour. That’s the challenge. The trick is to get to the point that you’re not worried about the lines, that they’re second nature. On a lot of films I’ve done, you’ll see people memorizing that day’s lines while they’re sitting in the makeup chair. You can’t do that with Aaron’s writing.”

Because we see McAvoy on the air as well as off, Daniels found himself forced to embody job skills that were out of his comfort zone.

“The challenge in playing Will McAvoy is finding the intelligence about world affairs, being able to fence with even the toughest interview subject,” he says. “I had to get on top of that so it looks like the news desk is my second home, as if I’d been doing this for 25 years. Will has a fierce intelligence about things that I personally haven’t even thought about. I’m saying words I’ve never said in my life.

“I’ve always been a news junkie and I’m interested in politics, in the machinations of it all. But Will’s got a knowledge and an ability to interview that I don’t have that’s crucial to the character.”

Daniels, still boyishly handsome at 57, lives in Michigan (where he was reared), but temporarily relocated to Hollywood from Thanksgiving 2011 to April 2012 to film the series (the pilot was shot in July 2011). The series came on the heels of God of Carnage, the massive Broadway hit for which he received a Tony Award nomination and in which he appeared in close to 400 performances in 2009 and part of 2010 (in two different stints in the cast, playing two different roles).

The play, his first on Broadway in more than 15 years, led indirectly to his being cast in “The Newsroom.” Partly, that had to do with the people he was associating with in the play: costar James Gandolfini and one of the play’s producers, Scott Rudin, who is also one of the producers of “The Newsroom.”

“As soon as Scott read the pilot, he mentioned Jeff’s name,” Sorkin says. “I felt lucky to get Jeff. I’ve been a fan of his since I saw him in The Fifth of July when I was in college, both off-Broadway and on.”

Still, it was all about the timing. Daniels had ignored series television for most of his career, because, aside from the fact that it rarely offered the kind of quality he sought, it also would have meant long absences from his family (he has three children) in Chelsea, Michigan, the hometown where he and his wife have lived since returning there in 1986.

But with his youngest daughter in college, Daniels (who has an apartment in New York) felt freer to take on a longer Broadway run like God of Carnage, and to consider a television series that would have him working in Hollywood for long stretches. So he consulted Carnage castmate Gandolfini.

“He asked me what to look for in a series and I said, ‘Get a great writer,’ ” Gandolfini says. “You need a great show-runner. The great TV shows have a guy or two in the front who are very passionate about the work. And he’s certainly got that in Aaron Sorkin. I think it’s a perfect vehicle for him.”

For his part, Daniels was looking for work that would challenge and fulfill him in the same way that films once had. While he still landed the occasional role in bigger budget studio films (such as 2009’s State of Play), those were fewer and farther between, which left the independent-film world. That offered some strong roles, including Bernard Berkman, the self-absorbed novelist and father in 2005’s The Squid and the Whale, for which he received a Golden Globe nomination, and the little-seen The Answer Man in 2009. But, again, those kinds of roles came along too seldom to be satisfying.

“I became disenchanted with the independent-film scene,” Daniels says. “I was getting offered a lot of ‘asshole father’ roles, after I did Squid and the Whale. People would say, ‘Oh, you were so great in that,’ and then I’d get a script with a role for an asshole father who was in about four scenes. I’ve done a lot of independent films and nobody sees those. And since the economy went south, half the independent distributors have folded. Things changed and, for a guy like me, they didn’t change for the better.

“HBO is where the writers are. After I looked at several things, along came this script by Aaron Sorkin—and I chased it.”And then HBO chased him: “When we read the pilot, in part because the character is a newscaster, there are whole pages of dialogue for him. We were wondering who could pull it off, because Aaron writes with a certain cadence that’s really challenging for a lot of actors,” Lombardo says. “So it had to be someone smart and fresh. Then Jeff’s name came up and we thought that was an interesting choice. He’s the right age, and he’s got the good looks. When he read for it, there was no question after we heard him that Jeff Daniels was the best choice. After he read, we couldn’t imagine anyone else. It was so clear that Jeff was made for this role.

“It was the perfect confluence of actor and role. You never see Jeff act; there’s an ease with which he inhabits the role. You never feel as though there’s a speech or a monologue going on; it’s just this character talking. Jeff does that better than any actor I’ve ever seen.”

It’s a quality Daniels had from the start—even before the start—of his career: the ability to mix the serious with the silly, to be funny and heartbreaking, glib and vulnerable within the same scene. His talent was apparent to Marshall Mason, one of the founders of New York’s Circle Repertory Company, who discovered Daniels while Mason was a visiting director at the University of Eastern Michigan one summer in the mid-1970s. “He was unusually honest in his work,” Mason says. “He had this natural, innate talent.”

Mason was a visiting professional at Eastern Michigan, imported to Ypsilanti in 1976 to direct a college production of Tennessee Williams’ Summer and Smoke for a summer repertory season. But he was having trouble casting the central male role, a young doctor who has an affair with a prim older woman.

“Then in walks this big blond boy, this big jock who looked like he’d strayed in from the football field,” Mason recalls. “It was Jeff; he was a student at Central Michigan—and his reading was a miracle. He put himself in my hands and did everything I asked in the exploration of the character.”

“I think Marshall saw a simplicity, an honesty and truthfulness in what the character was saying,” Daniels says. “I think I had that back then. I don’t know how, because I was very raw. Marshall would give me a direction and I’d execute it with a simplicity that I guess was unusual for a 21-year-old college actor.”

Says Mason, “Jeff was very funny but also very serious about the work. I talked to him about his experience and, in fact, he did play football. But he had also done musicals and plays at school and enjoyed that. He was just a natural, honest actor who showed a natural talent.

“I never encourage anyone to be an actor but I felt strongly about him. I said I’d do anything in my power to help him. I offered him an internship at Circle Rep, which paid, I believe, $50 a week, and he came to New York.”

It was the moment that changed Daniels’ life. He left Michigan for New York and, almost immediately, landed a role in a Circle Rep play visible enough to earn him an agent. He kept working there, and then playwright Lanford Wilson wrote a role specifically for him.

The play, The Fifth of July, played off-Broadway, then was presented in Los Angeles. When it went to Broadway—with a cast that included Christopher Reeve and Swoosie Kurtz—Daniels rode it all the way to a Tony Award nomination in 1981. Hollywood called shortly afterward—a small part in Milos Forman’s Ragtime, followed by career-making roles in Terms of Endearment and The Purple Rose of Cairo.

Asked what his life would have been like had he not met Mason during that fateful summer, Daniels shakes his head and offers a rueful smile.

“I would have gone to New York to try acting and maybe lasted a year,” he says. “I’d probably be back in Michigan, helping my brother run the lumber company with my dad. I’m not sure the lumber company would have been better off if that had happened. But the lumber company is still there and my dad and brother are still running it.

“I owe my career to Marshall,” he says. “Not only did he pull me out of Michigan, he kept me in New York. With each passing year, I knew more what I was doing—but I didn’t initially. But Marshall and Lanford kept saying, ‘You’re good. Stay here.’ ”

His parents were supportive, despite the fact that he hadn’t finished college: “Before Marshall came, they’d seen four years of me starring in high-school musicals and community theater. There was obviously something going on above and beyond what the other kids were doing. They knew that, somehow, this was what I should be doing. But they didn’t know how I should go about it.

“Then Marshall said, ‘I know what you should be doing with your life.’ He wanted me to drop out and go to Circle Rep. Here’s a guy from New York, saying, ‘Come join my theater company.’ And my parents said, ‘You should go.’ ”

Mason chuckles as he disputes one part of Daniels’ story: “If I’d known he had only finished his junior year and was leaving college to come, I never would have offered.”

The shock to Daniels’ system—moving from Michigan to Manhattan in the mid-1970s—was significant. “I came from a small town in the Midwest to Dante’s Inferno with Central Park,” he says. “That was a lot to deal with. But after two years, I was OK.”

Once he was launched in movies, he found himself working with a variety of directors whose work he admired, cast in leads in work as diverse as The Purple Rose of Cairo (in which he replaced Michael Keaton after Woody Allen decided Keaton was wrong for the role), Jonathan Demme’s Something Wild in 1986 and Robert Altman’s TV production of The Caine Mutiny Court-Martial in 1988.

“With Jonathan, you knew it was a Jonathan Demme movie just from the way he shot it,” Daniels says. “There was this energy he had—like he would have done it the same way whether the budget was $100 million or $100,000. It’s this excited attitude of ‘Look what we get to do for a living.’

“Bob Altman would create these train-wreck stagings, this kind of creative mess—and the messier the better. And it brought this surprising energy to the work. With Woody, well, I got to play not one but two roles. A lot of actors would have retired after that. The first thing Woody said was, ‘This script is not the Bible or written in stone. If you need to change it, go ahead.’ But, if he needed you to say it a certain way, he’d say so. Still, it made me want to say the lines word for word.

“Altman, Demme and Woody all shared this quality of saying, ‘Why don’t you do this and see what happens?’ and then they’d say, ‘Rolling.’ They were trying to make something happen during that first time between ‘Action!’ and ‘Cut!’ You might flame out, but if you don’t, then you might have something great. I call them happy accidents. You create them by winging it to see what happens.”

Daniels is a one-time cigar lover, who gave them up a few years back: “I was into Romeo y Julietas, the Cuban ones. It was partly the excitement of the contraband—who did you know who could get them from Canada? My grandfather and my uncle always had a cigar in their hands. So when I smoked, it always brought back fond memories.”

In his career, Daniels has played a rogues’ gallery of characters—everything from oily villains (State of Play) to cartoon characters made flesh (101 Dalmatians), from 19th-century war heroes (Gettysburg) to corporate bigshots (Good Night, and Good Luck) to taciturn lawmen (Infamous).

But his real love was theater—and so, when he and his wife moved back to Michigan, he put his energy into creating a professional company in his hometown. The Purple Rose Theater Company, which he founded in 1991 in Chelsea, started in a garage and has grown into one of the town’s economic mainstays, a regional center where theater professionals can work, playwrights can see their work performed and area residents can see professional theater in rural Michigan. (Chelsea is in the central part of Michigan’s lower peninsula, about 50 miles west of Detroit.) Daniels put his own time and money into the theater, writing plays for it that have become a regular part of its annual schedule.

“I’ve been involved with it for 20 straight years. They’ve done 14 of my plays and I have a 15th that will be part of the coming season,” he says. “Over the last few years, I’ve turned the running of the theater over to people who are there everyday. The actual management no longer needs or requires me.

“The theater was designed for professionals who maybe went to New York or Los Angeles but didn’t get a break. They’re back in Michigan, but they still have talent; it just went undiscovered. They’re Equity actors, and now they’ve got a professional theater within a half hour of their home.

“I brought back everything I learned at Circle Rep, that sense of collaboration with playwrights. Someone said to me that Purple Rose was born the day I set forth from Chelsea for Circle Rep.”

Daniels was able to satisfy his own long-dormant stage urge when he was cast in Yasmina Reza’s God of Carnage, which became the Tony Award-winning sensation of 2009. A four-character play in which he appeared with Gandolfini, Marcia Gay Harden and Hope Davis, it detailed an increasingly uncivilized meeting between two pairs of upscale New York parents who get together to discuss an act of playground violence by one couple’s son against the son of the other. The four actors argued, fought, destroyed property—and even dealt with a moment of projectile vomiting—in an intermission-free, 90-minute cage match, a dark comedy of recrimination and shifting alliances that ultimately pitted couple against couple, husband against wife and men against women.

“It was a real workout. If you weren’t in some state of exhaustion at the end, then you didn’t do it right,” Daniels recalls with a smile. “There were nights where I would verbally spit on Jim from across the stage and just treat him like shit. We’d get offstage and he’d say, ‘God, you’re being a sonuvabitch tonight.’ ”

Gandolfini praises Daniels for helping him through the rehearsal process: “I hadn’t done a play in a long time and Jeff was very patient,” he says. “We did 300-plus performances together and got along great. That was part of the success of the play.”

God of Carnage was a massive hit, playing to more than 100 percent of capacity during the original cast’s run. It was Broadway’s hottest ticket, attracting a who’s who to see it on a nightly basis: “Tony Bennett, Mike Nichols, Robert De Niro, James Earl Jones—all these people were coming backstage after the show,” Daniels recalls. “But we were so busy up there trying to make it work with the speed and precision that (director Matthew Warchus) demanded; that’s what we were focused on.”

After the original cast left and other actors came in for a while, Daniels returned to the show, taking over the role Gandolfini had played, with Janet McTeer as his wife: “I always wanted to be one of those guys who flipped roles,” Daniels says. “But I always felt I was renting the role from Jim. I gave it my best shot. But when he came back to the show when we did it in Los Angeles, I thought, ‘He owns it.’ ”

“I was better,” Gandolfini jokes, adding, “Jeff is an artist. He’ll try stuff like that. And he’s a good man, a regular guy.”Offstage, Daniels has a laconic presence, an observer who takes things in before offering his considered assessment. Gandolfini affectionately uses words like “curmudgeon” and “grumpy” to describe him. McTeer offers a similar appraisal.

“He’d sit there in rehearsal and be grumpy—and then come out with something brilliant because he’s very intelligent and clever,” she says. “Really, he was an absolute love to work with. We would riff off each other brilliantly. Every night on stage was different. It was like playing tennis with someone who is never in the wrong place. He really made me laugh every single show. It could be a Wednesday matinee where I was really tired and not sure I had a screaming match in me. He’d give me a kick in the bum by throwing a curveball and waking me up.”

Daniels has played smart, and he’s played dumb…and dumber—in, of course, Dumb and Dumber. Daniels says that playing dumb was a much tougher gig—at first.

“I was having nothing but difficulty in rehearsal, getting past caricature,” he says. “But I only needed one key thought to trigger the character. Sometimes actors make things too complicated. So I did two things. First, I said to myself, ‘I have an IQ of 8.’ Not 7, not 9, but 8. Once I did that, I literally could feel my brain relax; thoughts were leaving my head out of both ears. The other thing I did is that I would literally shake my head before each take, as though I was sloshing my brain around, so it was just this massive organ that was going unused.”

Dismissed by critics when it was released in 1994, Dumb and Dumber, which teamed Daniels with Jim Carrey in the first film by the Farrelly brothers, was a massive hit with audiences, holding the No. 1 spot in the box-office rankings for six straight weeks. Decried by social commentators of the time for dumbing down the level of movie comedy, it remains an audience favorite, a film that fans of all ages mention to Daniels when they stop him on the street.

Indeed, there has been considerable talk about a sequel. Though Daniels says, “The movie doesn’t have a green light yet,” he’d be happy to reprise the role of Harry Dunne, for a couple of reasons. “I’ve had 17 years of people of all ages who have seen and enjoyed it, and who’d like to see those two guys again,” he says. “The idea of two middle-aged guys being that stupid, naïve and oblivious is still funny.

“The serious reason is that I went to Walter Reed hospital, twice, to visit injured servicemen. You see a 19-year-old with no legs and one arm, who was in Iraq four days ago, who just wants to feel good again. When he looks up and one of the guys from Dumb and Dumber walks in, well, that movie is what he wants to talk about. He says, ‘It makes me laugh.’ To me, that’s as good a reason as any to do a sequel.”

The energy required for God of Carnage and the acting chops it honed are serving Daniels well in his new role in “The Newsroom.” While the play was a workout, starring in series television is more so.

Says Gandolfini: “The play was two hours and then you were done. With a series, you work all day, and then you go home and work some more, because you have to memorize crap for the next day. But it’s also incredibly fulfilling when the work is good. We talked about it before he took the show. After he started, he sent me an e-mail, saying, ‘I get it now.’ He waited a long time to do a series. And now he’s doing it in such a right way.”

For his part, Daniels says, “(The pilot) might be the best script I’ve read since The Purple Rose of Cairo. Aaron writes in a way that’s very exciting, very dangerous. He discovers it as he goes and HBO has given him the freedom to do that. One of the first things he said to me, after he asked whether I’d read the pilot, was, ‘Don’t worry—I’ll fix it.’ And it was great to start with.

“There’s a mental endurance you have to have to stay ahead of Aaron. You can’t have an off day or an episode where you feel like you don’t have to work so hard. I’ve been up and I’ve been down. This is up—creatively, it’s way up. I’m working hard because I don’t want my peers to look at this show and say, ‘I think I could have done it better.’

“Lanford Wilson used to say, ‘Make it matter. Make it count.’ And this show does. As Aaron said, each episode has to be the best yet.”

Contributing editor Marshall Fine writes about movies and entertainment on his website, www.hollywoodandfine.com.